Assume your 401(k) retirement account, on average, earns 7.5% annual interest.

Using the Rule of 70, calculate approximately how long does it take for your balance to double?

__________

(Round to the nearest tenth.)

If your balance starts out at $2,500, approximately how much would it be worth in 25 years?

$__________

(Round to the nearest dollar and do not use commas.)

Suppose the flavor of strawberries can have a flavor rating from 0 to 1, where 0 = no flavor at all and 1 = the best possible flavor (that is, when you first pick the strawberry from your awesome garden).

Now assume that through careful gardening research, you find that the average half-life of strawberry flavor is 4 days.

If you picked a strawberry from your garden 10 days ago, what fraction of the flavor remains? __________ (Write a decimal rounded to the nearest hundredth.)

Suppose that a severe virus is impacting a bee colony and the population of bees has a half-life of 5 days.

What approximate daily percentage of decay does the bee colony demonstrate? __________%

(Round to two decimals. Hint: use the Rule of 70 backwards by dividing by the half-life period instead of the rate.)

What percentage of the original bee colony would be surviving after 15 days of decay? __________%

(Round to two decimals.)

Question 8:

Suppose that the amount of water in a local water hole for cattle has a half-life of 14 days.

If the water hole initially contained 19,000 gallons of water, how much water would it contain after 25 days?

__________

(Round to the nearest whole number.)

After 70 days?

__________

(Round to the nearest whole number.)